SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f5867a430b0579c1eac5d338651bcd1a0199d1304d8506716c8729be67df264' 
  AND token = '4wxA2GFQ6rU0bLMq/SJPQUIKvgWRh4hlv2UpsOwZWRo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}